‘And he said to him, “Arise, and go your way. Your faith has made you whole.” '
Then He turned to the man and declared that his faith had ‘saved him', had made him whole. Thus it is made clear that non-Jews also could find salvation through faith in Jesus. The idea is not that the other nine were not saved. It is in order to stress that this ‘stranger' was saved.
The Future Glorious Appearing of The Son of Man (Luke 17:20-25).
The Pharisees are aware of Jesus' continual teaching concerning the coming of the Kingly Rule of God and approach Him to ask Him when it is coming. But their problem is that they are looking for the wrong thing. It is their view that the Messiah, once he has come, will in some way overturn the Romans, and will then establish Israel as a free, independent nation whose influence will reach out to the world, with them in overall authority. Thus they are looking for the establishment of a physical kingdom on earth of a type like other kingdoms (the kingdom of Herod, the kingdom of Philip, and so on). They have failed to recognise that much of what the prophets had promised could not in fact be fulfilled in a physical kingdom, and that Jesus had come bringing something better, the everlasting Kingdom promised by the prophets.
In His reply Jesus will bring out firstly that the Kingly Rule of God is already here and is being entered by those who believe in Him and follow Him, and secondly that the finalisation of that Kingly Rule will take place when He comes in glory. Thus they can be sure that any Messiah who comes in any other way is false. Such a one will not be the Son of Man as revealed in Daniel 7:13-14.
The passage can be analysed as follows:
a Being asked by the Pharisees, when the Kingly Rule of God is coming, He answered them and said, “The Kingly Rule of God is not coming with observation, nor will they say, Lo, here! or, There! for lo, the Kingly Rule of God is within (or ‘among') you” (Luke 17:20-21).
b He said to the disciples, “The days will come, when you will desire to see one of the days of the Son of man, and you will not see it” (Luke 17:22).
c “They will say to you, ‘Lo, there!' ‘Lo, here!' Go not away, nor follow after them” (Luke 17:23).
b “For as the lightning, when it lightens out of the one part under the heaven, shines to the other part under heaven, so shall the Son of man be in His day” (Luke 17:24).
a “But first must He suffer many things and be rejected of this generation” (Luke 17:25).
Note that in ‘a' the earthly aspect of the Kingly Rule of God is stressed, and in the parallel it is dependent on the earthly suffering and rejection of the Son of Man. In ‘b' there will be days when men desire to see the day of the Son of Man and will not see it, and in the parallel when His Day comes it will be in splendour as bright as lightning. And centrally in ‘c', once He has suffered, men are not to go looking for Him here on earth, (because when He does come it will be in glory that is revealed to the whole world). The centrality of this emphasises its importance. The purpose of this passage is finally in order to warn His disciples that in the coming days after He is gone they are not to be so overburdened with their task that they welcome some pseudo-Messiah.
But within it also we have a summary of Jesus' teaching concerning the present Kingly Rule of God and the glorious appearing of Himself as the Son of Man, which can only take place after He has suffered. It is in the light of this that all His previous teaching must be seen.